Apparatus for annealing



Patented Oct. 27, V1936 UNi'izED STATES y.austin ArrAnA'rUs Fon ANNEALING Albert W. Herman, Cleveland, Ohio, assigner Lee Wilson,l Cleveland, Ohio Application March 15, 1935, Serial No. 11,235

s claims.' (01266-5) sectional view showing a furnace generally of the type disclosed in the Wilson patent, `having the My invention relates to the art of annealing and,` in particular, to the annealing of thin sheet metal in the form of strip or sheets.

'It .has now become `quite common to anneal e strip coils or .sheets by disposing them on a base, covering them with a metallic inner cover, and lowering thereover a refractory-lined furnace bell or outer cover having aheating means therein. An example of this apparatus and method is disclosed in United States Patent No. 1,952,402, granted March 27, 1934, to Lee Wilson, except that the inner cover is not shown. The inner coversare subject to distortion and warpage in use because of the fact that they are repeatedly heated to relatively high temperatures, and then cooled, Y in the conventional annealing cycle.

Various expedients have been employed to prevent this distortion or warpage but none of these, so far as I am aware, have been successful. Re- .inforcing frames have been incorporated in some inner covers but these are of little value because the frames themselves warp and lose their original shape. Y Q A I have invented a method and apparatus for eliminating or retarding warpage ofv the inner covers used with furnace bells of the type mentioned in the aforementioned Wilson patent. I n accordance with my invention, I provide movable bracing or supporting members'4 on the interior '3 of the furnaceJ cover and operable,preferably from without the furnace; into or out of engagement .with the inner cover, to afford lateral support and bracing therefor during the heating portion of the annealing cycle. The inner cover .35 must be made' of relatively thin sheet metal in order to permit rapid transmission of heat to the material to be annealed, which is enclosed thereby. This requirement, of course, tends to prevent the covers from being made strong enough to be 40 entirely self-supporting, particularly at elevated temperatures.

cause of th warpa'geand distortion referred to.

' My invention permits the inner covers to be braced laterally when heated, without materially 45 affecting the transmission of heat from the exterior lof the cover to the interior therein. It is also useful for straightening covers which have.

become warped in use.

For acomplete understanding of the invention,

- 5`0 reference is made to the accompanyiligdrawing illustrating a present preferred embodiment, Valthough it will be understood that changes in the construction and practice there indicated may be made `within the scope of my broader claims.l .55 The single figure of the drawlngisa transverse This, l; believe. is the principal invention incorporated therein.

Referring now in detail tothe drawing, an annealing furnace I0 comprises a base il includ- .5

-ing a refractory hearth I2 supported on a struc-4 tural framework I3.` 'Ihe hearth has a plate Il providing a surface to receive the material to be annealed. 'Ihe furnace I0 also includes a cover or bell I5 including side walls I6, end'walls l1, V10 and a roof i8 all assembled within a suitable enclosure indicated generallyat I9. The sidewalls I6 of the outer cover or furnace bell are provided with'heat-radiating tubes 2liV `having suitable burners (not shown) and exhaust 15 stacks 2|, as disclosed more fully 'and claimed in .copenl g application Serial No. 7,905 of Lee Wilson, filed February 23,A 1935. Each of the side walls is provided with a plurality ofthe tubes and they are spaced uniformly therealong. 2o

A depending iiange 22 at the lower edge of the side and end walls vof the cover extends into auid seal provided by a channel 23 disposed along the sides .and ends of the base Il. A similar channel 24 extends around the plate il and is 25 filled with sand tor seal the joint between the base li and an inner cover 25. 'Ihe 'cover 25 vconsists simply of an open-bottomed box formed of metallic plate, the lower edges of which enter the sand-filled channel 24. The material to be moved into engagement witlrthe side walls of the 40 cover 25 during the heating portion of the annealing cycle. 'Ihe bars 21 are shown vertical but may be disposed in any convenient manner and it will be understood that I provide a plurality of them on each side of the furnace, depending on the llength thereof, to brace the side walls of the annealing cover at appropriately spaced points. The bars 21- are carried on sliderods 2 8 extending through the side walls of the furnace between adjacent tubes 20. For this purpose, the side lwalls have holes 29 and seals SII.

The bracing bars 21 may be operated through 'theslide rods 28 in any convenient manner but I prefer to employ hand levers 3| pivoted tothe slidegrgds as the latter-are to vthe 21, the

side of the furnace.

levers 3| being pivoted at 32 to a fixed bearing carried by the enclosure for the outer cover. The ends of the levers 3| remote from their connection with the rodsw28 are preferably provided with pawls 33 adapted to cooperate with curved ratchet plates 34 attached to the exterior of the furnace bell. The pawls of the upper levers 3| have counterweights35 which normally hold the pawls in engagement with the teeth of the ratchet plates. 'Ihe pawls of the lower levers are normally held in such engagement by their own weight and have tips 36 by which the pawls may be manually held out of engagement when it is desired to release the levers and withdraw the bars 21. The counterweights 35 of the pawls of the upper levers may be similarly lifted forA this purpose.

The operation of the structure described hereinabove will doubtless be apparent from what has been said. The bars 2l are normally retracted, as shown in the drawing on the left When the outer cover or furnace bell has been lowered into the position shown, the levers 3| are manually pushed in carrying the guide bars'2'l to the position shown on the right in the drawing. When all the levers have been pushed home, the inner cover is tightly secured th-erebetween and braced laterally against deformation or warpage of the walls thereof. When the furnace bell is to be removed, the levers 3| are released and the bracing bars 2`| retracted.

It will be apparent from the above description that the invention provides novel and highly useful means for limiting or preventing distortion and warping' of inner covers, with the result that their useful life is considerably extended over previous practice, and the total cost of annealing thereby materially reduced. 'I'he invention is useful not only in preventing or limiting warpage of the walls of the inner covers but also may be `employed to straighten warped covers when they have been heated in\the normal operation o f the furnace, to the' proper temperature. While the invention has been shown as applied particularly to the side walls of the furnace, it may also be applied to the end walls with equal facility. The furnace bell or outer cover is rigidly constructed and the invention described herein makes it possible to employ the rigidity of the outer cover to support vthe inner cover which, as stated, 'must necessarily be o'f light construction in order to transmit heat rapidly and, therefore, has little inherent strength or rigidity of its own.

The bracing means, in addition to being applied to the side walls and ends of the furnace bell, may

also be provided in the roof or the base. Thel presented.

placed by hooks on the rods 28, adapted to enl gage eyes on the inner cover. By this means anoutward force may be exerted on the coversl where desirable.

Although I have described and illustrated here in but one preferred form and practice of the invention, it will be apparent that numerous changes therein may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim: 1. Annealing apparatus comprising a. furnace. slide rods extending through the furnace wall, and bracingvbars carried on the slide rods for engaging and laterally supporting a cover within the furnace enclosing the material to be annealed.

2. The apparatus defined by claim 1 characterized by means operable from the exterior of th furnace for actuating the bars.

3. The combination with an annealing furnace of a plurality of bracing bars movably carriedV on the interior thereof adapted to engage and laterally support an enclosure for the material being annealed, of means operable from. without the furnace for retracting and Vadvancing said bars.

4. In an annealing furnace, slide rods movably mounted in a Wall thereof, and a bracing bar carried on said rods for engaging an enclosure Within the furnace for the material to be treated.

5. The apparatus defined by claim 4 characterized by levers mounted exteriorly of the furnace for operating said rods.

6. The apparatus defined by-claim 4 characterized by levers mounted exteriorly of the furnace for operating said rods, and means for locking said levers in operated position.

7. Annealing apparatus comprising a furnace having a hearth adapted to support the material to be annealed, a cover adapted to be disposed within the furnace over said material and on said hearth, said cover having a side Wall and a top, and means carried by the furnace and extending inwardly therefrom for applying pressure to said side wall.

8. Annealing apparatus comprising a furnace having a hearth, side walls and a roof, an enclosure for the material to be annealed having a side wall and a top and adapted to be disposed within the furnace on said hearth, and means slidable through the side walls of the furnace and engaging said side wall of the enclosure to provide lateral support for the latter.

9. Annealing apparatus comprising a furnace having a cover and a hearth adapted to receive material to be annealed, movable means extending inwardly from the furnace for supporting the cover disposed over the material, and means for operating said movable means from the exterior of the furnace.

, ALBERT W. HERMAN. 

